In the discussion that follows, reference is made to certain structures and/or process. However, the following references should not be construed as an admission that these structures and/or process constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or process do not qualify as prior art against the present invention.
In conventional polycrystalline diamond compact processes (PDC), high pressure and high temperature (HPHT) is applied to diamond powder that is adjacent to a cemented carbide substrate, pre-sintering. During sintering, the binder of the carbide sweeps through the diamond powder to create the PDC. In conventional processes, a cobalt (Co) disc layer doped with silicon (Si) is placed between the diamond powder and the carbide prior to sintering in order to introduce silicon to protect the PDC from graphitization. Unfortunately, during the sweep, the silicon is present during the sintering process. Consequently, silicon carbide (SiC) is formed and prevents the diamond grains from being well sintered together. FIG. 1 shows a flow diagram 100 of a conventional process of creating a polycrystalline diamond compact (PDC) 104. In the conventional process, a diamond powder/grit 101 is deposited in a metal container 108, where the diamond powder/grit 101 is adjacent to a cemented carbide substrate 102. To manufacture the PDC, high pressure and high temperature (HPHT) is applied to commence sintering. After the HPHT process is started, a binder content originating in the cemented carbide substrate 102, such as cobalt, sweeps across the top face 103 between the cemented carbide substrate 102 and the diamond powder/grit 101 to inside of the diamond powder/grit 101. After a period of time, e.g., from 10 seconds to 10 minutes, when sweeping is completed, the sintered diamond/PDC 104 are left to cool. The presence of Si in the cemented carbide substrate 102 layer may hinder the production of a good PDC 104 by either creating silicon carbide (SiC) phases between the diamond powder/grit 101, or through some other hindering mechanism. This hindering manifests itself in sweeping cobalt silicide or chromium silicide, for example. Poor performance has been observed, such as poor wear resistance and delamination, for example.
Although one solution to the sweeping of the Si across the cemented carbide substrate 102 layer is to not use the Co disc doped with Si, it is desired that the PDC 104 be protected from, for example, graphitization during drilling due to a silicon carbide (SiC) coating around the pores between of the diamond grains.